"This summer, she and the crown prince have been touring the western, most beautiful part of Norway, and I believe the TV images from the representation they did has gained her popularity," said Kavli.
Inevitably, some have compared the blond, photogenic Mette-Marit to another photogenic princess.
"[Some people] think she is another Diana. I don't think she is that," said Tessem.
For one thing, said Tessem, becoming a member of the Norwegian royal family is nowhere near as daunting as joining the Windsor clan.
"The Norwegian royal family is much more relaxed than the English royal family was," she said. "I don't think you can compare the two families at all."
A Series of Accidents
As she adjusts to her royal role, Mette-Marit has had to get used to the constant media attention. In February, there was a scene aboard a plane when she thought she was being photographed.
"She accused a photographer of taking a picture of her in the cabin. She was very upset because she had asked that no one take pictures because she is afraid of flying," said Tessem. "She was very upset and angry.
"The pressure is obviously very strong. I think that was very difficult for her," said Tessem.
"She's getting used to posing and having photographers on her official events, but it's a hard thing to cope with the interest in her private life."
Mette-Marit has also been plagued by a series of ailments. After attending the Winter Olympics in Salt Lake City, she came down with pneumonia. Then she broke her ankle during an Easter ski trip.
In May, Mette-Marit and her husband were severely sunburned during an interview with a German TV crew. The strong spring sun, combined with reflection from the camera lights, scorched the couple so badly that they sustained first- and second-degree burns.
"The sunburn was quite scary," said Tessem. "The crown princess was very badly burned; she had open wounds."
The injuries forced her to bow out of an official trip to Germany, but no one thought she was shirking her royal duties. "She had a high degree of sympathy in the population," said Kavli.
Mette-Marit has also received a lot of sympathy and support from her mother-in-law, Queen Sonja, said Tessem.
The queen herself was a commoner until she married the future King Harald V in 1968. Harald's father, King Olav V, reportedly took some convincing before he consented to the match.
"The queen has been very supportive and very helpful" to her new daughter-in-law, Tessem said.
And Mette-Marit is not the only commoner to marry into the royal family this year. Haakon's sister, Princess Martha Louise, married hip young novelist Ari Behn in May.
Behn was a somewhat controversial choice because he had been seen as condoning drug use during an appearance in a TV documentary. An MMI poll found only one in 10 Norwegians consider Behn a good role model, Kavli said.
Kavli said the addition of Mette-Marit had not really boosted the popularity of the royal family, but he thinks that's really more a question of people not being used to her, a sort of "We like the royal family the way it is."
"I suspect her popularity will rise in this respect as the Norwegian population gets used to the idea that Mette-Marit is royalty, too."
Studying in London